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By NASA
6 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
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A thick torus of gas and dust surrounding a supermassive black hole is shown in this artist’s concept. The torus can obscure light that’s generated by material falling into the black hole. Observations by NASA telescopes have helped scientists identify more of these hidden black holes.NASA/JPL-Caltech An effort to find some of the biggest, most active black holes in the universe provides a better estimate for the ratio of hidden to unhidden behemoths.
Multiple NASA telescopes recently helped scientists search the sky for supermassive black holes — those up to billions of times heavier than the Sun. The new survey is unique because it was as likely to find massive black holes that are hidden behind thick clouds of gas and dust as those that are not.
Astronomers think that every large galaxy in the universe has a supermassive black hole at its center. But testing this hypothesis is difficult because researchers can’t hope to count the billions or even trillions of supermassive black holes thought to exist in the universe. Instead they have to extrapolate from smaller samples to learn about the larger population. So accurately measuring the ratio of hidden supermassive black holes in a given sample helps scientists better estimate the total number of supermassive black holes in the universe.
The new study published in the Astrophysical Journal found that about 35% of supermassive black holes are heavily obscured, meaning the surrounding clouds of gas and dust are so thick they block even low-energy X-ray light. Comparable searches have previously found less than 15% of supermassive black holes are so obscured. Scientists think the true split should be closer to 50/50 based on models of how galaxies grow. If observations continue to indicate significantly less than half of supermassive black holes are hidden, scientists will need to adjust some key ideas they have about these objects and the role they play in shaping galaxies.
Hidden Treasure
Although black holes are inherently dark — not even light can escape their gravity — they can also be some of the brightest objects in the universe: When gas gets pulled into orbit around a supermassive black hole, like water circling a drain, the extreme gravity creates such intense friction and heat that the gas reaches hundreds of thousands of degrees and radiates so brightly it can outshine all the stars in the surrounding galaxy.
The clouds of gas and dust that surround and replenish the bright central disk may roughly take the shape of a torus, or doughnut. If the doughnut hole is facing toward Earth, the bright central disk within it is visible; if the doughnut is seen edge-on, the disk is obscured.
A supermassive black hole surrounded by a torus of gas and dust is depicted in four different wavelengths of light in this artist’s concept. Visible light (top right) and low-energy X-rays (bottom left) are blocked by the torus; infrared (top left) is scattered and reemitted; and some high energy X-rays (bottom right) can penetrate the torus. NASA/JPL-Caltech Most telescopes can rather easily identify face-on supermassive black holes, though not edge-on ones. But there’s an exception to this that the authors of the new paper took advantage of: The torus absorbs light from the central source and reemits lower-energy light in the infrared range (wavelengths slightly longer than what human eyes can detect). Essentially, the doughnuts glow in infrared.
These wavelengths of light were detected by NASA’s Infrared Astronomical Satellite, or IRAS, which operated for 10 months in 1983 and was managed by NASA’s Jet Propulsion Laboratory in Southern California. A survey telescope that imaged the entire sky, IRAS was able to see the infrared emissions from the clouds surrounding supermassive black holes. Most importantly, it could spot edge-on and face-on black holes equally well.
IRAS caught hundreds of initial targets. Some of them turned out to be not heavily obscured black holes but galaxies with high rates of star formation that emit a similar infrared glow. So the authors of the new study used ground-based, visible-light telescopes to identify those galaxies and separate them from the hidden black holes.
To confirm edge-on, heavily obscured black holes, the researchers relied on NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array), an X-ray observatory also managed by JPL. X-rays are radiated by some of the hottest material around the black hole. Lower-energy X-rays are absorbed by the surrounding clouds of gas and dust, while the higher-energy X-rays observed by NuSTAR can penetrate and scatter off the clouds. Detecting these X-rays can take hours of observation, so scientists working with NuSTAR first need a telescope like IRAS to tell them where to look.
NASA’s NuSTAR X-ray telescope, depicted in this artist’s concept, has helped astronomers get a better sense of how many supermassive black holes are hidden from view by thick clouds of gas and dust that surround them.NASA/JPL-Caltech “It amazes me how useful IRAS and NuSTAR were for this project, especially despite IRAS being operational over 40 years ago,” said study lead Peter Boorman, an astrophysicist at Caltech in Pasadena, California. “I think it shows the legacy value of telescope archives and the benefit of using multiple instruments and wavelengths of light together.”
Numerical Advantage
Determining the number of hidden black holes compared to nonhidden ones can help scientists understand how these black holes get so big. If they grow by consuming material, then a significant number of black holes should be surrounded by thick clouds and potentially obscured. Boorman and his coauthors say their study supports this hypothesis.
In addition, black holes influence the galaxies they live in, mostly by impacting how galaxies grow. This happens because black holes surrounded by massive clouds of gas and dust can consume vast — but not infinite — amounts of material. If too much falls toward a black hole at once, the black hole starts coughing up the excess and firing it back out into the galaxy. That can disperse gas clouds within the galaxy where stars are forming, slowing the rate of star formation there.
“If we didn’t have black holes, galaxies would be much larger,” said Poshak Gandhi, a professor of astrophysics at the University of Southampton in the United Kingdom and a coauthor on the new study. “So if we didn’t have a supermassive black hole in our Milky Way galaxy, there might be many more stars in the sky. That’s just one example of how black holes can influence a galaxy’s evolution.”
More About NuSTAR
A Small Explorer mission led by Caltech and managed by NASA’s Jet Propulsion Laboratory in Southern California for the agency’s Science Mission Directorate in Washington, NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp. in Dulles, Virginia. NuSTAR’s mission operations center is at the University of California, Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center at NASA’s Goddard Space Flight Center. ASI provides the mission’s ground station and a mirror data archive. Caltech manages JPL for NASA.
For more information on NuSTAR, visit:
www.nustar.caltech.edu
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Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
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Last Updated Jan 13, 2025 Related Terms
NuSTAR (Nuclear Spectroscopic Telescope Array) Astrophysics Black Holes Galaxies, Stars, & Black Holes Jet Propulsion Laboratory The Universe Explore More
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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
LMS instrument aboard the Blue Ghost Lander heading to Mare Crisium in mid-January
As part of its Artemis campaign, NASA is developing a series of increasingly complex lunar deliveries and missions to ultimately build a sustained human presence at the Moon for decades to come. Through the agency’s CLPS (Commercial Lunar Payload Services) initiative, commercial provider Firefly’s Blue Ghost lander will head to the Moon’s Mare Crisium for a 14-day lunar lander mission, carrying NASA science and technology that will help understand the lunar subsurface in a previously unexplored location.
From within the Mare Crisium impact basin, the SwRI-led Lunar Magnetotelluric Sounder (LMS) may provide the first geophysical measurements representative of the bulk of the Moon. Most of the Apollo missions landed in the region of linked maria to the west (left image), whose crust was later shown to be compositionally distinct (right image) as exemplified by the concentration of the element thorium. Mare Crisium provides a smooth landing site on the near side of the Moon outside of this anomalous region. NASA Developed by the Southwest Research Institute (SwRI), NASA’s Lunar Magnetotelluric Sounder (LMS) will probe the interior of the Moon to depths of up to 700 miles, two-thirds of the way to the lunar center. The measurements will shed light on the differentiation and thermal history of our Moon, a cornerstone to understanding the evolution of solid worlds.
Magnetotellurics uses natural variations in surface electric and magnetic fields to calculate how easily electricity flows in subsurface materials, which can reveal their composition and structure.
“For more than 50 years, scientists have used magnetotellurics on Earth for a wide variety of purposes, including to find oil, water, and geothermal and mineral resources, as well as to understand geologic processes such as the growth of continents,” said SwRI’s Dr. Robert Grimm, principal investigator of LMS. “The LMS instrument will be the first extraterrestrial application of magnetotellurics.”
Mare Crisium is an ancient, 350-mile-diameter impact basin that subsequently filled with lava, creating a dark spot visible on the Moon from Earth. Early astronomers who dubbed dark spots on the moon “maria,” Latin for seas, mistook them for actual seas.
Mare Crisium stands apart from the large, connected areas of dark lava to the west where most of the Apollo missions landed. These vast, linked lava plains are now thought to be compositionally and structurally different from the rest of the Moon. From this separate vantage point, LMS may provide the first geophysical measurements representative of most of the Moon.
The Lunar Magnetotelluric Sounder (LMS) will probe the interior of the Moon to depths of up to 700 miles or two-thirds of the lunar radius. The measurements will shed light on the differentiation and thermal history of our Moon, a cornerstone to understanding the evolution of solid worlds.
NASA’s Goddard Space Flight Center The LMS instrument ejects cables with electrodes at 90-degree angles to each other and distances up to 60 feet. The instrument measures voltages across opposite pairs of electrodes, much like the probes of a conventional voltmeter. The magnetometer is deployed via an extendable mast to reduce interference from the lander. The magnetotelluric method reveals a vertical profile of the electrical conductivity, providing insight into the temperature and composition of the penetrated materials in the lunar interior.
“The five individual subsystems of LMS, together with connecting cables, weigh about 14 pounds and consume about 11 Watts of power,” Grimm said. “While stowed, each electrode is surrounded by a ‘yarn ball’ of cable, so the assembly is roughly spherical and the size of a softball.”
The LMS payload was funded and will be delivered to the lunar surface through NASA’s CLPS initiative. Southwest Research Institute based in San Antonio built the central electronics and leads the science investigation. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provided the LMS magnetometer to measure the magnetic fields, and Heliospace Corp. provided the electrodes used to measure the electrical fields.
Under the CLPS model, NASA is investing in commercial delivery services to the Moon to enable industry growth and support long-term lunar exploration. As a primary customer for CLPS deliveries, NASA aims to be one of many customers on future flights. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the development of seven of the 10 CLPS payloads carried on Firefly’s Blue Ghost lunar lander.
Media Contact: Rani Gran
NASA’s Goddard Space Flight Center, Greenbelt, Maryland
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Last Updated Jan 10, 2025 EditorRob GarnerContactRani GranLocationGoddard Space Flight Center Related Terms
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By NASA
Humans are returning to the Moon—this time, to stay. Because our presence will be more permanent, NASA has selected a location that maximizes line-of-sight communication with Earth, solar visibility, and access to water ice: the Lunar South Pole (LSP). While the Sun is in the lunar sky more consistently at the poles, it never rises more than a few degrees above the horizon; in the target landing regions, the highest possible elevation is 7°. This presents a harsh lighting environment never experienced during the Apollo missions, or in fact, in any human spaceflight experience. The ambient lighting will severely affect the crews’ ability to see hazards and to perform simple work. This is because the human vision system, which despite having a high-dynamic range, cannot see well into bright light and cannot adapt quickly from bright to dark or vice versa. Functional vision is required to perform a variety of tasks, from simple tasks (e.g., walking, operating simple tools) through managing complex machines (e.g., lander elevator, rovers). Thus, the environment presents an engineering challenge to the Agency: one that must be widely understood before it can be effectively addressed.
In past NASA missions and programs, design of lighting and functional vision support systems for extravehicular activity (EVA) or rover operations have been managed at the lowest program level. This worked well for Apollo and low Earth orbit because the Sun angle was managed by mission planning and astronaut self-positioning; helmet design alone addressed all vision challenges. The Artemis campaign presents new challenges to functional vision, because astronauts will be unable to avoid having the sun in their eyes much of the time they are on the lunar surface. This, combined with the need for artificial lighting in the extensive shadowing at the LSP, means that new functional vision support systems must be developed across projects and programs. The design of helmets, windows, and lighting systems must work in a complementary fashion, within and across programs, to achieve a system of lighting and vision support that enables crews to see into darkness while their eyes are light-adapted, in bright light while still dark-adapted, and protects their eyes from injury.
Many of the findings of the assessment were focused on the lack of specific requirements to prevent functional vision impairment by the Sun’s brilliance (which is different from preventing eye injury), while enabling astronauts to see well enough to perform specific tasks. Specifically, tasks expected of astronauts at the LSP were not incorporated into system design requirements to enable system development that ensures functional vision in the expected lighting environment. Consequently, the spacesuit, for example, has flexibility requirements for allowing the astronauts to walk but not for ensuring they can see well enough to walk from brilliant Sun into a dark shadow and back without the risk of tripping or falling. Importantly, gaps were identified in allocation of requirements across programs to ensure that the role of the various programs is for each to understand functional vision. NESC recommendations were offered that made enabling functional vision in the harsh lighting environment a specific and new requirement for the system designers. The recommendations also included that lighting, window, and visor designs be integrated.
The assessment team recommended that a wide variety of simulation techniques, physical and virtual, need to be developed, each with different and well-stated capabilities with respect to functional vision. Some would address the blinding effects of sunlight at the LSP (not easily achieved through virtual approaches) to evaluate performance of helmet shields and artificial lighting in the context of the environment and adaptation times. Other simulations would add terrain features to identify the threats in simple (e.g., walking, collection of samples) and complex (e.g., maintenance and operation of equipment) tasks. Since different facilities have different strengths, they also have different weaknesses. These strengths and limitations must be characterized to enable verification of technical solutions and crew training.
NESC TB 2024- discipline-focus-hfView the full article
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By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Regolith Adherence Characterization, or RAC, is one of 10 science and technology instruments flying on NASA’s next Commercial Lunar Payload Services (CLPS) flight as part of the Blue Ghost Misison-1. Developed by Aegis Aerospace of Webster, Texas, RAC is designed to study how lunar dust reacts to more than a dozen different types of material samples, located on the payload’s wheels. Photo courtesy Firefly Aerospace The Moon may look like barren rock, but it’s actually covered in a layer of gravel, pebbles, and dust collectively known as “lunar regolith.” During the Apollo Moon missions, astronauts learned firsthand that the fine, powdery dust – electromagnetically charged due to constant bombardment by solar and cosmic particles – is extremely abrasive and clings to everything: gloves, boots, vehicles, and mechanical equipment. What challenges does that dust pose to future Artemis-era missions to establish long-term outposts on the lunar surface?
That’s the task of an innovative science instrument called RAC-1 (Regolith Adherence Characterization), one of 10 NASA payloads flying aboard the next delivery for the agency’s CLPS (Commercial Lunar Payload Services) initiative and set to be carried to the surface by Firefly Aerospace’s Blue Ghost 1 lunar lander.
Developed by Aegis Aerospace of Webster, Texas, RAC will expose 15 sample materials – fabrics, paint coatings, optical systems, sensors, solar cells, and more – to the lunar environment to determine how tenaciously the lunar dust sticks to each one. The instrument will measure accumulation rates during landing and subsequent routine lander operations, aiding identification of those materials which best repel or shed dust. The data will help NASA and its industry partners more effectively test, upgrade, and protect spacecraft, spacesuits, habitats, and equipment in preparation for continued exploration of the Moon under the Artemis campaign.
“Lunar regolith is a sticky challenge for long-duration expeditions to the surface,” said Dennis Harris, who manages the RAC payload for NASA’s CLPS initiative at the agency’s Marshall Space Flight Center in Huntsville, Alabama. “Dust gets into gears, sticks to spacesuits, and can block optical properties. RAC will help determine the best materials and fabrics with which to build, delivering more robust, durable hardware, products, and equipment.”
Under the CLPS model, NASA is investing in commercial delivery services to the Moon to enable industry growth and support long-term lunar exploration. As a primary customer for CLPS deliveries, NASA aims to be one of many customers on future flights. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the development of seven of the 10 CLPS payloads carried on Firefly’s Blue Ghost lunar lander.
Learn more about. CLPS and Artemis at:
https://www.nasa.gov/clps
Alise Fisher
Headquarters, Washington
202-358-2546
Alise.m.fisher@nasa.gov
Headquarters, Washington
202-358-2546
Alise.m.fisher@nasa.gov
Corinne Beckinger
Marshall Space Flight Center, Huntsville, Ala.
256-544-0034
corinne.m.beckinger@nasa.gov
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Last Updated Dec 20, 2024 EditorBeth RidgewayContactCorinne M. Beckingercorinne.m.beckinger@nasa.govLocationMarshall Space Flight Center Related Terms
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By NASA
NASA-supported scientists have suggested an updated framework for the role of ferns in environmental recovery from disaster. Instead of competing with other organisms, ferns may act as facilitators that ease the way for other plants and animals to re-establish themselves in a damaged landscape.
The study examines how a biosphere recovers from major upheaval, be it from wildfires or asteroid impacts, using what scientists call a ‘facilitative’ framework (where the actions of organisms help each other) rather than the long-held ‘competition-based’ framework.
NASA supported researchers at a fossil plant quarry near the Old Raton Pass Cretaceous–Paleogene (K-Pg) boundary in New Mexico.Ellen Currano Ferns are a common type of vascular plant found in woodlands, gardens, and many a plant pot on apartment shelves. Unlike many other vascular plants, ferns do not flower or seed. Instead, they reproduce via spores. Ferns first appeared on Earth some 360 million years ago during the Devonian period and, prior to the evolution of flowering plants, were the most common vascular plant on Earth.
Ferns are often one of the first plants to re-establish in areas affected by large-scale upheaval events, and it has been suggested that this is because ferns produce spores in great amounts that are widely distributed on the wind. Some scientists, particularly in the fields of geology and paleontology, have used this ‘competitive’ success of ferns as a foundation for ecological theories about how recolonization happens after upheavals.
However, in recent years, growing research has shown that recovery is not only about competition. Positive interactions, known as facilitation, between ferns and other species also play a significant role. The authors of the recent study believe that it is time to re-examine positive interactions within ecosystems, rather than defaulting to a competition framework.
Ferns in History
“I love to imagine ecosystems through time and play a game in my head where I ask myself, ’if I could stand here for 1 million years, would this fossilize?’” said lead author Lauren Azevedo Schmidt of the University of California at Davis. “Because of the mental time gymnastics I do, my research questions follow the same pathway. How do I create synergy between modern and paleo research?”
Early Paleocene fern fossil discovered on the Vermejo Park Ranch, NM. Photo by Ellen Currano.Ellen Currano The team examined ideas that have been developed based on observing modern organisms as well as ancient populations in the fossil record. They propose that, rather than out-competing other species, ferns act as facilitators for ecosystem recovery by stabilizing the ground, enhancing properties of the soil, and mediating competition between other organisms. This repositions ferns as facilitators of ecological recovery within disturbed habitats. This has broad implications for understanding how a community recovers and the importance of positive interactions following disturbance events. Because ferns are among the oldest lineages of plants on Earth and have experienced unimaginable climates and extinction events, they provide critical information to better understand the fossil record and Earth before humans.
Fossil plant excavation in the Cretaceous rocks just below the K-Pg boundary at Old Raton Pass, NM. Photo by Ellen Currano.Ellen Currano “The Cretaceous – Paleogene [K-Pg] extinction event reworked Earth’s biosphere, resulting in approximately 75% of species going extinct, with up to 90% of plants going extinct,” said Azevedo Schmidt. “This magnitude of devastation is something humans (luckily) have never had to deal with, making it hard to even think about. But it is something we must consider when tackling research/issues surrounding exobiology.”
The longevity of ferns on Earth provides a view into the evolution of life on Earth, even through some of the planet’s most devastating disasters. This is of interest to astrobiology and exobiology because exploring how environmental factors can and have impacted the large-scale evolution of life on Earth through mass extinctions and mass radiation events can help us understand the potential for the origin, evolution and distribution for life elsewhere in the Universe.
Ferns in Space
In addition to their relevance to astrobiology, the resilience of ferns and their ability to help heal a damaged environment could also make them important partners for future human missions in space. NASA’s Space Biology program has supported experiments to study how plants adapt to space with the expectation that knowledge gained can lead to ways by which crops can be cultivated for fresh food. Lessons learned from studying resilient plants, such as ferns, could guide efforts to make crops adapt better to harsh space conditions so they can serve as a reliable food source as humans explore destinations beyond our planet. Previous studies have also looked at how plants might keep air clean in enclosed spaces like the International Space Station or in habitats on the Moon or Mars.
NASA supported scientists can be seen prospecting for plant fossils in Berwind Canyon, CO. Photo by Ellen Currano.Ellen Currano “Ferns were able to completely transform Earth’s biosphere following the devastation of the K-Pg [Cretaceous–Paleogene] extinction event. The environment experienced continental-scale fires, acid rain, and nuclear winter, but ferns were able to tolerate unbelievable stress and make their environment better,” says Azevedo Schmidt. “I think we can all learn something from the mighty ferns.”
The study, “Ferns as facilitators of community recovery following biotic upheaval,” was published in the journal BioScience [doi:10.1093/biosci/biae022]
For more information on NASA’s Astrobiology program, visit:
https://www.science.nasa.gov/astrobiology
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Karen Fox / Molly Wasser
Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
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